What causes stains on car glass?
Minerals from sprinkler and bore water bond to glass over time, and traffic leaves road film on it. Both build up into a haze that the wipers smear instead of clearing. Your fingernail not catching tells you nothing deep is cut in. Hard water left long enough can still etch the surface lightly.
What kind of repair does it need?
Cleaning the glass properly, then polishing if the deposits have been there long enough to etch. A glass cleaner made for mineral scale dissolves it. A clay bar lifts what is stuck on top. A glass polish takes out light etching.
A different trade from paint. Past a certain depth, glass is replaced rather than polished.
What to do next
A detailer for the film and scale. A glass specialist if it has etched in. It is worth doing, because a lot of night glare and wiper smearing is this, not the blades. If someone quotes a new windscreen for haze you cannot feel, get a second opinion.
Sources
- J.Racenstein (glass cleaning supplier)product seller
Calcium and magnesium minerals bond to the surface over time…
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